WSB: Breeding wolves vulnerable to wolf harvest

The legal wolf harvest in Idaho disproportionately affects breeding individuals—males and females that lead packs—during the breeding season.

Previous research reveals that removing these individuals from packs can hinder population growth.

“Those breeders are more vulnerable during the breeding season—they have breeding on the mind,” said Peter Rebholz, a research biologist at the University of Idaho.

In a study published recently in Wildlife Society Bulletin, Rebholz and his colleagues identified breeders from tissue samples from wolves harvested in Idaho. Then, they determined what proportion of the harvested wolves were breeders and what season they were harvested in.

Using genetic analysis, the researchers could identify breeders when they could compare the genes from tissue samples from parents—gray wolf (Canis lupus) packs typically only have one breeding couple—and direct descendants.

They found that breeding wolves were disproportionately harvested in January and February—their breeding season.

This may be due to breeders often being the first to investigate scent lures or predator calls. “Breeders [are] the first in a fight—the first to defend the territory—and in the breeding season, they are even more ramped up,” Rebholz said.

He said that wildlife managers can use this information to adjust or remove seasonal hunting regulations, depending on whether the goal is to have more or fewer wolves on the landscape.

It’s also possible that removing these breeders has other effects on pack behavior. Pack leaders usually guide hunts and know their territory better than other individuals.

Removing the breeders could cause packs to break up, and the movements of individuals may become more erratic for a period of time, as individuals set out to form new packs or join other preexisting ones.

“The longer a breeding pair is together, the more successful that pack tends to be in terms of hunting, raising young, and, a lot of times, staying out of the way of humans,” Rebholz said.

This article features research that was published in a TWS peer-reviewed journal. Individual online access to all TWS journal articles is a benefit of membership. Join TWS now to read the latest in wildlife research.